Energy harvesting mattress with thermoelectric fabric

ABSTRACT

Energy harvesting mattresses, systems, and methods of cooling mattresses are disclosed herein. In some aspects, the energy harvesting mattress can include a body support having a proximal surface that is configured to support a sleeper and a flexible thermoelectric fabric comprising at least one p-type layer coupled to at least one n-type layer to provide at least one p-n junction. The flexible thermoelectric fabric can be configured to be in thermal communication with the proximal surface of the body support such that when the proximal surface is heated the flexible thermoelectric fabric generates a current.

CROSS REFERENCE TO RELATED APPLICATIONS

This Non-Provisional application claims the benefit of U.S. ProvisionalPatent Application Ser. No. 62/134,156 filed on Mar. 17, 2015, which isfully incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure generally relates to mattress assemblies,specifically to energy harvesting mattress assemblies usingthermoelectric fabric.

In order to maintain homeostasis the human body produces thermal andkinetic energy during sleep that is then subsequently dissipated to theenvironment. Both forms of energy can be harvested through severalmethods to generate power (e.g., for small electronic devices, tricklecharge batteries, and the like.) Current methods for harvesting energyare inefficient and/or cumbersome.

Thermoelectric systems have been employed in attempts to capture energy.For example, an existing design (e.g., WO2014062187 A1) has been notedto use multiple thermoelectric components spaced about the interior of amattress. The separation between components decreases effectiveness, asthe heat transferred to areas without components is not used ingenerating electricity. An increase in the number of components woulddecrease mattress comfort as the components featured are not flexible orconforming. The sparse positioning of the components causes a decreasein efficacy in relation to the sleeper's position on the mattress assleepers must remain in an ideal position above the components in orderto generate maximum electricity. The sparse positioning of thecomponents in WO 2014062187 A1, for example, causes a decrease ineffectiveness in relation to the sleeper's position on the mattress.Sleepers must remain in an ideal position above the components in orderto realize maximum power generation. The rigid nature of thethermoelectric components requires that they be buried deeper into themattress in order to maintain comfort which further decreases theireffectiveness. Moreover, rigid thermoelectric components are expensiveto produce thus making them undesirable for mattress applications.

Accordingly, there remains a need for improved systems, devices, andmethods of harvesting energy in mattress assemblies. Specifically,systems, devices, and methods that are less costly to produce, morecomfortable, more easily integrated, and would provide more welldistributed functionality on a large surface such as a mattress aredesired.

SUMMARY

In some aspects, an energy harvesting mattress can include a bodysupport having a proximal surface that is configured to support asleeper and a flexible thermoelectric fabric comprising at least onep-type layer coupled to at least one n-type layer to provide at leastone p-n junction. The flexible thermoelectric fabric can be configuredto be in thermal communication with the proximal surface of the bodysupport such that when the proximal surface is heated the flexiblethermoelectric fabric generates a current.

In other aspects, an energy harvesting mattress assembly can include abody support having a proximal surface that is configured to support asleeper and a flexible thermoelectric fabric for harvesting thermal andkinetic energy. The flexible thermoelectric fabric can have at least onep-type layer coupled to at least one n-type layer to provide at leastone p-n junction. Furthermore, the flexible thermoelectric fabric can bein thermal communication with the proximal surface of the body supportsuch that when the proximal surface is heated the flexiblethermoelectric fabric generates a current, and the flexiblethermoelectric fabric can be disposed along the proximal surface of thebody support such that when kinetic energy is transferred to theproximal surface of the body support, the flexible energy harvestingfabric generates a current.

The above described and other features are exemplified by theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

This disclosure will be more fully understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a side view of an expanded thermoelectric apparatus that canform a flexible thermoelectric fabric;

FIG. 2 is an exemplary thermoelectric apparatus;

FIG. 3 is a side view of an exemplary flexible thermoelectric fabric;

FIG. 4 is a perspective cut-away view of an exemplary mattress assemblythat includes a flexible thermoelectric fabric;

FIG. 5 is a cut-away view of an exemplary mattress assembly thatincludes a flexible thermoelectric fabric;

FIG. 6 is a perspective view of an exemplary flexible thermoelectricfabric;

FIG. 7 is a diagram of a Peltier effect with respect to a flexiblethermoelectric fabric; and

FIG. 8 is a diagram of a Seebeck effect with respect to a flexiblethermoelectric fabric.

DETAILED DESCRIPTION

Certain exemplary aspects will now be described to provide an overallunderstanding of the principles of the structure, function, manufacture,and use of the devices, systems, methods, and/or kits disclosed herein.One or more examples of these aspects are illustrated in theaccompanying drawings. Those skilled in the art will understand that thedevices, systems, methods, and/or kits disclosed herein and illustratedin the accompanying drawings are non-limiting and exemplary in natureand that the scope of the present invention is defined solely by theclaims. The features illustrated or described in connection with any oneaspect described may be combined with the features of other aspects.Such modification and variations are intended to be included within thescope of the present disclosure.

Further in the present disclosure, like-numbered components generallyhave similar features, and thus each feature of each like-numberedcomponent is not necessarily fully elaborated upon. Additionally, to theextent that linear or circular dimensions are used in the description ofthe disclosed systems, devices, and methods, such dimensions are notintended to limit the types of shapes that can be used in conjunctionwith such systems, devices, and methods. A person skilled in the artwill recognize that an equivalent to such linear and circular dimensionscan be determined for any geometric shape. Sizes and shapes of thesystems and devices, and the components thereof, can depend at least onthe size and shape of the components with which the systems and deviceswill be used, and the methods and procedures in which the systems anddevices will be used.

Flexible thermoelectric fabrics have been developed for use in variousapplications. For example and without limitation, thermoelectric fabricsare disclosed in U.S. Publication No. 2013/0312806, which is titled“Thermoelectric Apparatus and Applications Thereof” and is herebyincorporated by reference in its entirety. These fabrics can employ theSeebeck effect through a layered p-n junction material to generateelectricity from a thermal gradient. Modules of the material may bearranged in series, parallel, or a combination in order to achieve thedesired voltage and current ratings. The thermoelectric fabric remainsflexible due to its polymeric construction. This allows for retainedcomfort when placing the layers proximal to a mattress surface, where asleeper may be generating heat and where the thermal gradient is larger,generating electricity more efficiently. The term “sleeper” generallyrefers to a user of the mattress, which can include the user's bodyheat. Thermoelectric fabrics can also cover an entire sleep surface ifneeded. This can decrease the positional requirements of the sleeperallowing them to move freely in the mattress while still experiencinguniform temperature distribution and energy harvesting (i.e., this canallow for continuous electricity generation). The use of athermoelectric fabric as means to harvesting thermal and kinetic energymoves the mechanism closer to the body surface, increasing efficiency.The flexible nature of the thermoelectric fabric can allow it to remainunnoticed to the sleeper (i.e., transparent), maintaining comfort whileproviding improved efficacy.

Flexible, polymer-based thermoelectric fabrics can be constructedthrough the lamination of doped p- and n-junction polymers separated byan insulating material. These laminated modules can be stacked andarranged in series, parallel or a combination in order to achieve thedesired energy harvesting. Polymer based thermoelectric fabrics can beplaced nearer the surface of a mattress to increase efficiency of theenergy harvesting process.

Flexible thermoelectric fabrics can also be piezoelectric. As usedherein, “piezoelectric” and/or “piezoelectric energy harvesting” meansthe generation of electricity from kinetic motion distributed throughthe fabric. For example and without limitation, the thermoelectricfabrics produced through the methods of U.S. Publication No.2013/0312806 also have the benefit of being piezoelectric. This meansthat they generate electricity from the thermal gradient across thefabric as well as from kinetic motion distributed through the fabric.The combination of thermoelectric and piezoelectric effects dramaticallyincreases efficiency of the energy harvesting process. Placing thesematerials near the surface of a mattress can generate enough electricityto charge or power external loads, such as small electronic devicesincluding but not limited to alarm clocks, cell phones, sensors andbiofeedback devices. Energy expended by a sleeping person could then beharvested and used to generate electricity to power these devices. Insome aspects, power generation capabilities of thermoelectric fabricscan achieve at least about 0.2 W/m². Additionally, in some aspects,power generation capabilities of thermoelectric fabrics can achieve atleast about 0.8 W/m². Therefore, as one of ordinary skill in the artwill understand, assuming a 1.0 m² contact area on a mattress for anaverage male sleeper, efficiency rates of the described thermoelectricfabric can be enough to charge an external load such as a cell phone.Table 1 illustrates example thermoelectric, piezoelectric, and combinedenergy generation data for an example thermoelectric fabric according tosome aspects of the present disclosure.

TABLE 1 Energy Harvesting Thermoelectric Piezoelectric Max Stroke MaxCombined ΔT (K) TE (W/m²) Hz (m) PE (W/m²) Combined (W/m²) 10 0.1 10.00001 0.1 0.2 10 0.4 1 0.00001 0.4 0.8

As is explained in greater detail in U.S. Publication No. 2013/0312806,FIG. 1 illustrates an expanded side view of a thermoelectric apparatusthat forms example flexible thermoelectric fabrics. The thermoelectricapparatus illustrated in FIG. 1 comprises two p-type layers 1 coupled toan n-type layer 2 in an alternating fashion. The alternating coupling ofp-type 1 and n-type 2 layers provides the thermoelectric apparatus az-type configuration having p-n junctions 4 on opposite sides of theapparatus. Insulating layers 3 are disposed between interfaces of thep-type layers 1 and the n-type layer 2 as the p-type 1 and n-type 2layers are in a stacked. configuration. As shown, the thermoelectricapparatus provided in FIG. 1 is in an expanded state to facilitateillustration and understanding of the various components of theapparatus. In some aspects, however, the thermoelectric apparatus is notin an expanded state such that the insulating layers 3 are in contactwith a p-type layer 1 and an n-type layer 2.

FIG. 1 additionally illustrates the current flow through thethermoelectric apparatus induced by exposing one side of the apparatusto a heat source. Electrical contacts X are provided to thethermoelectric apparatus for application of the thermally generatedcurrent to an external load.

Again as is explained in greater detail in U.S. Publication No.2013/0312806, FIG. 2 illustrates an example thermoelectric apparatus 200wherein the p-type layers 201 and the n-type layers 202 are in a stackedconfiguration. The p-type layers 201 and the n-type layers 202 can beseparated by insulating layers 207 in the stacked configuration. Thethermoelectric apparatus 200 can be connected to an external load byelectrical contacts 204, 205.

FIG. 3 illustrates an example flexible thermoelectric fabric 300. Theflexible thermoelectric fabric 300 can comprise a thermoelectricapparatus as described above with respect to FIGS. 1-2 such that theapparatus forms a fabric that is capable of bending easily withoutbreaking. As such, in some aspects, the flexible thermoelectric fabriccan comprise at least one p-type layer coupled to at least one n-typelayer to provide a p-n junction, and an insulating layer at leastpartially disposed between the p-type layer and the n-type layer, thep-type layer comprising a plurality of carbon nanoparticles and then-type layer comprising a plurality of n-doped carbon nanoparticles. Insome aspects, carbon nanoparticles of the p-type layer are p-doped andcarbon nanoparticles of the n-type layer are n-doped. In some aspects, ap-type layer of a flexible thermoelectric fabric or apparatus canfurther comprise a polymer matrix in which the carbon nanoparticles aredisposed. In some aspects, an n-type layer further comprises a polymermatrix in which the n-doped carbon nanoparticles are disposed. In someaspects, p-type layers and n-type layers of a flexible thermoelectricfabric or apparatus described herein are in a stacked configuration.

In some aspects, carbon nanoparticles of a p-type layer comprisefullerenes, carbon nanotubes, or mixtures thereof In some aspects,carbon nanotubes can comprise single-walled carbon nanotubes (SWNT),multi-walled carbon nanotubes (MWNT), as well as p-doped single-walledcarbon nanotubes, p-doped multi-walled carbon nanotubes or mixturesthereof N-doped carbon nanoparticles can comprise fullerenes, carbonnanotubes, or mixtures thereof In some aspects, n-doped carbon nanotubescan also comprise single-walled carbon nanotubes, multi-walled carbonnanotubes, or mixtures thereof.

In some aspects, a p-type layer and/or n-type layer can further comprisea polymeric matrix in which the carbon nanoparticles are disposed. Anypolymeric material not inconsistent with the objectives of the presentinvention can be used in the production of a polymeric matrix. In someaspects, a polymeric matrix comprises a fluoropolymer including, but notlimited to, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF),polytetrafluoroethylene (PTFE), or mixtures or copolymers thereof. Insome aspects, a polymer matrix comprises polyacrylic acid (PAA),polymethacrylate (PMA), polymethylmethacrylate (PMMA) or mixtures orcopolymers thereof In some aspects, a polymer matrix comprises apolyolefin including, but not limited to polyethylene, polypropylene,polybutylene or mixtures or copolymers thereof A polymeric matrix canalso comprise one or more conjugated polymers and can comprise one ormore semiconducting polymers.

As a person of ordinary skill will understand, the “Seebeck coefficient”of a material is a measure of the magnitude of an induced thermoelectricvoltage in response to a temperature difference across that material. Ap-type layer, in some aspects, can have a Seebeck coefficient of atleast about 3 μV/K at a temperature of 290° K. In some aspects, a p-typelayer has a Seebeck coefficient of at least about 5 μV/K at atemperature of 290° K. In some aspects, a p-type layer has a Seebeckcoefficient of at least about 10 μV/K at a. temperature of 290° K. Insome aspects, a p-type layer has a Seebeck coefficient of at least about15 μV/K or at least about 20 μV/K at a temperature of 290° K. In someaspects, a p-type layer has a Seebeck coefficient of at least about 30μV/K at a temperature of 290° K. A p-type layer, in some aspects, has aSeebeck coefficient ranging from about 3 μV/K to about 35 μV/K at atemperature of 290° K. In some aspects, a p-type layer has Seebeckcoefficient ranging from about 5 μV/K to about 35 μV/K at a temperatureof 290° K. In some aspects, a p-type layer has Seebeck coefficientranging from about 10 μV/K to about 30 μV/K at a temperature of 290° K.As described herein, in some aspects, the Seebeck coefficient of ap-type layer can be varied according to carbon nanoparticle identity andloading. In some aspects, for example, the Seebeck coefficient of ap-type layer is inversely proportional to the single-walled carbonnanotube loading of the p-type layer.

Similarly, an n-type layer can have a Seebeck coefficient of at leastabout −3 μV/K at a temperature of 290° K. In some aspects, an n-typelayer has a Seebeck coefficient at least about −5 μV/K at a temperatureof 290° K. In some aspects, an n-type layer has a Seebeck coefficient atleast about −10 μV/K at a temperature of 290° K. In some aspects, ann-type layer has a Seebeck coefficient of at least about −15 pV/K or atleast about −20 μV/K at a temperature of 290° K. In some aspects, ann-type layer has a Seebeck coefficient of at least about −30 μV/K at atemperature of 290° K. An n-type layer, in some aspects, has a Seebeckcoefficient ranging from about −3 μV/K to about −35 μV/K at atemperature of 290° K. In some aspects, an n-type layer has Seebeckcoefficient ranging from about −5 μV/K to about −35 μV/K. at atemperature of 290° K. In some aspects, an n-type layer has Seebeckcoefficient ranging from about −10 to about −30 μV/K at a temperature of290° K. In sonic aspects, the Seebeck coefficient of an n-type layer canbe varied according to n-doped carbon nanoparticle identity and loading.in some aspects, for example, the Seebeck coefficient of an n-type layeris inversely proportional to the carbon nanoparticle loading of then-type layer.

As described herein and in U.S. Publication No. 2013/0312806, in someaspects the flexible thermoelectric fabric can include an insulatinglayer. An insulating layer can comprise one or more polymeric materials.Any polymeric material not inconsistent with the objectives of thepresent invention can be used in the production of an insulating layer.In sonic aspects, an insulating layer comprises polyacrylic acid (PAA),polymethacrylate (PMA), polymethylmethacrylate (PMMA) or mixtures orcopolymers thereof. In some aspects, an insulating layer comprises apolyolefin including, but not limited to polyethylene, polypropylene,polybutylene or mixtures or copolymers thereof In sonic aspects, aninsulating layer comprises PVDF. An insulating layer can have anydesired thickness not inconsistent with the objectives of the presentinvention. In some aspects, an insulating layer has a thickness of atleast about 50 nm. In some aspects, an insulating layer has a thicknessranging from about 5 nm to about 50 μm. Additionally, an insulatinglayer can have any desired length not inconsistent with the objectivesof the present invention. In some aspects, an insulating layer has alength substantially consistent with the lengths of the p-type andn-type layers between which the insulating; layer is disposed. That is,in some aspects, an insulating layer, p-type layer, and/or n-type layercan have a length of at least about 1 μm, In some aspects, an insulatinglayer, p-type layer, and/or n-type layer can have a length ranging fromabout 1 μm to about 500 mm.

In use, the flexible thermoelectric fabric can be incorporated into amattress assembly. In so doing, the mattress assembly can be configuredto be a temperature control mattress and, additionally or alternatively,can be configured to produce an electric charge. FIG. 4 illustrates anexample mattress assembly 400 having a body support 402. The bodysupport 402 has a proximal surface 404 that can support a body 406. Thebody 406, as shown, can be a human body and the body support 402 can beconfigured to support the body in a prone, supine, semi-supine, sitting,or any other position so long as the body support 402 supports someportion of the body.

FIG. 5 illustrates an example mattress assembly 500. As shown, themattress assembly 500 can have an inner support 502 and a body supportsurface 504. In some aspects, the inner support 502 can be any of aspring, foam, air, or any other core support structure known in the art.The body support surface 504 can, as shown, include a variety of layers506, 508, 510, 512, 514. The layers can be formed of any supportmaterial including foams, gels, fabrics, down feathers, or any otherknown support material. Additionally, the layers 506, 508, 510, 512, 514can be configured to allow heat to transfer from the proximal surface orproximal most layer 506 to the distal most layer 514. As such, aflexible thermoelectric fabric can be disposed between any of layers506, 508, 510, 512, 514. Alternatively and/or additionally, any of thelayers 506, 508, 510, 512, 514 can be formed of an example flexiblethermoelectric fabric in accordance with the disclosures made herein.For example, layer 506 can be a decorative quilt mattress topper. Insome aspects, the quilt topper 506 can be formed of a flexiblethermoelectric fabric.

As shown in FIG. 6, the flexible thermoelectric fabric 608 can be formedof stacked p-layers, n-layers, and insulation layers, as is describedabove. As such, the flexible thermoelectric fabric 608 can be configuredto utilize the Peltier effect to cool a portion of the mattress assemblyand/or the Seebeck effect to harvest energy from the mattress assembly.As used herein and as a person of ordinary skill will understand, the“Peltier effect” means the presence of heating or cooling at anelectrified junction of two different conductors. Further, as a personof ordinary skill will understand, the “Seebeck effect” means an inducedthermoelectric voltage in response to a temperature difference across amaterial.

FIG. 7 illustrates an example diagram of the Peltier effect, which canresult in cooling of the body support surface when the flexiblethermoelectric fabric is disposed such that it is in thermalcommunication with the proximal surface of the body support. In thismanner, the top-most layer 702 of the fabric is cooled as charge movesthrough the p-layer 704 and n-layers 706 accordingly. As such, heat isdissipated along a bottom-most surface 708 of the fabric as thep-layer(s) and n-layer(s) are connected by a circuit 710.

FIG. 8 illustrates an example diagram of the Seebeck effect, which canresult in energy harvesting, i.e., the generation of an electricalvoltage when the flexible fabric is heated at the proximal surface ofthe body support, such as when a human lays on the body support andtransfers its body heat into the proximal surface of the body support.As shown, the top-most surface 802 of the fabric is exposed to a heatsource—e.g., a sleeper's body heat—and the bottom-most surface 808 is ata temperature that is cooler than the top-most layer 802. Voltage isgenerated by the system when the p-layers 804 are connected to then-layers 806 with a load resistor 810.

Thus, in some aspects, either to maximize temperature regulation of thesleeping surface (i.e., the proximal surface of the body support) or tomaximize a current generated by the flexible fabric, the fabric can bedisposed along an entire proximal surface of a mattress. As wasdescribed above, for example, a mattress topper can be formed entirelyof flexible thermoelectric fabric. Alternatively, the fabric can bestrategically located along portions of the fabric so as to maximizethermal communication between the proximal surface and the fabric. Thatis, the fabric can be placed in any manner that is consistent withabsorbing a desired and/or optimal amount of body heat from a body.Additionally, the flexible nature of the example thermoelectric fabricsprovide various advantages as described herein. For example, they areless costly to produce, more comfortable, more easily integrated andwould provide more well distributed functionality on a large surfacesuch as a mattress. The above disclosure solves positional and comfortissues by allowing for uniform thermal control decreasing hot spots orcold spots. This in turn also allows the sleeper to move freely withoutsensing changes in the cooling/heating system efficiency andfurthermore, allows for the thermoelectric system to be near the surfaceof the mattress for greater efficiency.

With respect to the above description, it is to be realized that theoptimum composition for the parts of the invention, to includevariations in components, materials, size, shape, form, function, andmanner of operation, assembly and use, are deemed readily apparent toone skilled in the art, and all equivalent relationships to thoseillustrated in the examples and described in the specification areintended to be encompassed by the present invention. Therefore, theforegoing is considered as illustrative only of the principles of theinvention. Further, various modifications may be made of the inventionwithout departing from the scope thereof, and it is desired, therefore,that only such limitations shall be placed thereon as are set forth inthe appended claims.

What is claimed is:
 1. An energy harvesting mattress, comprising: a bodysupport having a proximal surface that is configured to support asleeper; and a flexible thermoelectric fabric comprising at least onep-type layer coupled to at least one n-type layer to provide at leastone p-n junction, wherein the flexible thermoelectric fabric isconfigured to be in thermal communication with the proximal surface ofthe body support such that when the proximal surface is heated theflexible thermoelectric fabric generates a current.
 2. The mattress ofclaim 1, wherein the flexible thermoelectric fabric is configured toapply the generated current to an external load.
 3. The mattress ofclaim 1, wherein the flexible thermoelectric fabric is furtherconfigured for piezoelectric energy harvesting.
 4. The mattress of claim1, wherein the flexible thermoelectric fabric generates at least about0.2 W/m².
 5. The mattress of claim 1, wherein the flexiblethermoelectric fabric is disposed along the entire proximal surface ofthe body support.
 6. The mattress of claim 1, wherein the flexiblethermoelectric fabric comprises plurality of p-type layers coupled to aplurality of n-type layers to provide a plurality of p-n junctions. 7.The mattress of claim 6, wherein the plurality of p-type layers have aSeebeck coefficient of at least about 3 μV/K at 290° K.
 8. The mattressof claim 6, wherein the plurality of n-type layers have a Seebeckcoefficient of at least about −3 μV/K at 290° K.
 9. The mattress ofclaim 1, wherein the flexible thermoelectric fabric further comprises atleast one insulating layer.
 10. The mattress of claim 1, wherein theflexible thermoelectric fabric comprises a plurality of carbonnanotubes.
 11. A mattress assembly, comprising: a body support having aproximal surface that is configured to support a sleeper; and a flexiblethermoelectric fabric for harvesting thermal and kinetic energy havingat least one p-type layer coupled to at least one n-type layer toprovide at least one p-n junction, wherein the flexible thermoelectricfabric is in thermal communication with the proximal surface of the bodysupport such that when the proximal surface is heated the flexiblethermoelectric fabric generates a current, and the flexiblethermoelectric fabric is disposed along the proximal surface of the bodysupport such that when kinetic energy is transferred to the proximalsurface of the body support, the flexible energy harvesting fabricgenerates a current.
 12. The mattress of claim 11, wherein the flexiblethermoelectric fabric is configured to apply the generated current to anexternal load.
 13. The mattress of claim 11, wherein the flexiblethermoelectric fabric generates at least about 0.2 W/m².
 14. Themattress of claim 11, wherein the flexible thermoelectric fabric isdisposed along the entire proximal surface of the body support.
 15. Themattress of claim 11, wherein the flexible thermoelectric fabriccomprises plurality of p-type layers coupled to a plurality of n-typelayers to provide a plurality of p-n junctions.
 16. The mattress ofclaim 15, wherein the plurality of p-type layers have a Seebeckcoefficient of at least about 3 μV/K at 290° K.
 17. The mattress ofclaim 15, wherein the plurality of n-type layers have a Seebeckcoefficient of at least about −3 μV/K at 290° K.
 18. The mattress ofclaim 11, wherein the flexible thermoelectric fabric further comprisesat least one insulating layer.
 19. The mattress of claim 11, wherein theflexible thermoelectric fabric comprises a plurality of carbonnanotubes.
 20. The mattress of claim 19, wherein a portion of the carbonnanotubes are single-walled carbon nanotubes.